Decoherence mitigation by real-time noise acquisition

Abstract

We present a scheme to neutralize the dephasing effect induced by classical noise on a qubit. The scheme builds upon the key idea that this kind of noise can be recorded by a classical device during the qubit evolution, and that its effect can be undone by a suitable control sequence that is conditioned on the measurement result. We specifically demonstrate this scheme on a nitrogen-vacancy (NV) center that strongly couples to current noise in a nearby conductor. By conditioning the readout observable on a measurement of the current, we recover the full qubit coherence and its intrinsic coherence time $T_2$. We demonstrate that this scheme provides a simple way to implement single-qubit gates with an infidelity of $10^{-2}$ even if they are driven by noisy sources, and we estimate that an infidelity of $10^{-5}$ could be reached with additional improvements. We anticipate this method to find widespread adoption in experiments using fast control pulses driven from strong currents, in particular in nanoscale magnetic resonance imaging, where control of peak current s of 100 mA with a bandwidth of 100 MHz is required.

References in corpus (21)

• High-sensitivity diamond magnetometer with nanoscale resolution
• A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise
• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Quantum teleportation using active feed-forward between two Canary Islands
• How to Enhance Dephasing Time in Superconducting Qubits
• Quantum feedback control of a superconducting qubit: Persistent Rabi oscillations
• Room temperature quantum bit storage exceeding 39 minutes using ionized donors in 28-silicon
• High-speed linear optics quantum computing using active feed-forward
• Spectral multiplexing for scalable quantum photonics using an atomic frequency comb quantum memory and feed-forward control
• Spectroscopy of Surface-Induced Noise Using Shallow Spins in Diamond
• Single Ion Quantum Lock-In Amplifier
• Single-spin magnetometry with multi-pulse sensing sequences
• Suppressing qubit dephasing using real-time Hamiltonian estimation
• Quantum metrology enhanced by repetitive quantum error correction
• Controlling the quantum dynamics of a mesoscopic spin bath in diamond
• Fourier Magnetic Imaging with Nanoscale Resolution and Compressed Sensing Speed-up using Electronic Spins in Diamond
• Competition between electric field and magnetic field noise in the decoherence of a single spin in diamond
• Prediction and real-time compensation of qubit decoherence via machine-learning
• Measuring nanoscale magnetic write head fields using a hybrid quantum register
• Proposal for detection of a single electron spin in a microwave resonator
• Robust Dynamical Decoupling for Arbitrary Quantum States of a Single NV Center in Diamond